Frollo is one of the more human villains that Disney has. You don't see many Disney bad guys having such base driving passions as lust and fear of eternal fire. We still have Scar, Gaston, Hades and Ursula.

But yes, in the original cartoon, Khan is seen as not much more than a driving plot point, whereas in the movie he's a lot more terrifying and understandable. And with Idris Elba voicing him, he gets that little bit of extra touch.